Numerous devices have been designed for installing tags made of resilient elastomeric material of the type having a laterally extensive base for receiving indicia, an anchoring head in the general plan form of an arrowhead with a narrow leading end or tip and rearwardly diverging locking flanges joined to the base by a narrow neck. Each of these installing tools has been characterized by the fact that it includes a sharp cutting edge for cutting a slit in the ear and normally pulls or pushes the anchoring head through the slot along with the cutting blade until the anchoring head is on the opposite side of the ear and locked in place. Various installing tools have been devised for cutting a slit in the ear, rolling over the wings of the anchoring head so that they may be pushed through the slit and reopened on the other side to lock the tag in the ear. One of the first such devices is disclosed in my U.S. Pat. No. 3,552,051 wherein the anchoring head is rolled up and inserted in the end of a tubular handle on an intalling tool. Another such device is shown in my U.S. Pat. No. 3,850,360 wherein the anchoring head overlies the blade and a retaining member overlies the anchoring head. Another tool is shown in my U.S. Pat. No. 4,000,744 wherein the anchoring head is received in slots in the blade of the tool for installation. Still another tool is disclosed in my copending U.S. patent application Ser. No. 909,044, filed May 24, 1978, in which the locking flanges of the ear tag are placed in parallel vertical slots in the blade and the anchoring head is carried through the slit in the ear by the blade as it passes through the ear.
Certain disadvantages characterize each of these devices. One major deficiency with the installing tools of the prior art is that in some cases the entire tool must pass through the slit in the ear which increases the chance of tearing of the flesh adjacent the slit. In other devices, the blade, as well as the anchoring head and perhaps a retaining member, must all pass through the slit at the same time which again increases the possibility of tearing. With those installing tools where a push-pull motion is used to slit the ear and install the tag, it is again necessary to have both the blade and the anchoring head in the slit at the same time. Since the slit is made by the blade alone, it does not have in all cases sufficient height to accommodate both the blade and the thickness of the anchoring head without tearing the flesh at the ends of the slit.